An error occurs when an Exchange server 2003 user tries to open more than one delegate mailbox of Exchange Server 2010 in Outlook 2003

When a Microsoft Office Outlook 2003 user of a mailbox on Microsoft Exchange Server 2003 tries to open more than one additional mailbox or a shared folder from more than one mailbox that is homed on Exchange Server 2010, one of the following error messages is generated:
The set of folders could not be opened.
The information store could not be opened.
Unable to display the folder. The information store could not be opened.
Note This problem does not occur if the Exchange Server 2003 mailbox user only opens one delegated mailbox or shared folder from only one mailbox of Exchange Server 2010 in Outlook 2003.
Exchange Server 2003 mailboxes use the Activity Directory service as the source for directory information. Outlook 2003 relies on the Directory Referral mechanism to retrieve directory information. However, Exchange Server 2010 does not support the Directory Referral mechanism. In the scenario that is described in "Symptoms," Exchange Server 2010 requires the Outlook clients to retrieve directory information by using Exchange Address Book Service together with the constructed ExchangeLegacyDN attribute. However, Exchange Server 2003 does not recognize the constructed ExchangeLegacyDN attribute. Therefore, the error problem occurs.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.


Before you install this hotfix for Exchange Server 2003, you must install Exchange Server 2003 Service Pack 2 (SP2).
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
836993 How to obtain the latest service packs for Exchange Server 2003

Restart requirement

You do not have to restart the computer after you apply this hotfix.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.
File nameFile versionFile sizeDateTime

Article ID: 979690 - Last Review: 05/17/2010 23:31:56 - Revision: 2.0

Microsoft Exchange Server 2003 Service Pack 2

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